Progress on analysis of the field equations accelerated in the 1980s with the availability of English translations [1]} of work by Thiry [2]} under Lichnerowicz. During the 1980s and 1990s, significant work was done on the Kaluza theory, including a general solution for the 5D metric of a charged object [3]}, analogous to the Schwarzschild and Reissner-Nordstrom solutions.
